I'm David Friedman, a professional photographer who sometimes gets ideas for photos, designs, gadgets, and other projects. I write about it all on this blog. You can find the meaning behind the name “Ironic Sans” back in the very first post.

Likely Media
When I'm not writing the blog, I make a living as a photographer and filmmaker. This is my business website.

Sunday MagazineAt this site, I republish the most interesting articles from the New York Times Sunday Magazine exactly 100 years ago each week, along with some commentary or context.

March 29, 2006

Idea: The Ishihara Triptych

Remember when you were in third grade and the school nurse gave you that test to see if you’re color blind? The one where she shows you a circle made up of smaller colored circles and asks you what number you see? That test is the Ishihara Test of Color Vision.

I’m fascinated by perception, especially by the uncommon traits that make some people’s perception different than the rest of us — color blindness, tetrachromatism, synesthesia, monocular vision, etc. I also enjoy original art. I decided to combine the two interests by making a triptych out of three Ishihara color vision test plates.

At greater expense than I anticipated, I obtained a set of Ishihara color vision test plates. I picked out three plates that I felt looked good together, and blew them up to a size suitable for framing. The entire finished triptych, seen above, hangs above my bed. I think it makes a compelling piece of art.

It’s titled “57-74-8, or 35-21-3”

Want to make your own? Click each thumbnail below to download a high-res image you can download, print out, and frame.

I’m fascinated by your capacity to consistently generate interesting and compelling ideas…i suspect you’re a very fun person to be around..probably child-like (in a good way). Most people just aren’t that in touch with themselves to freethink the way you do..

Well, I downloaded the images, opened them in Photoshop and played with the “Hue/Saturation” tool. (It easily changes the overall color of an image). And I was able to see 35, 31, and 3.

Download the hi-res of each image.
Look at the 57 image (first one).
Within the green dots, there’s a few dark green dots grouped together that help form the number 35. You have to combine certain areas of the pinkish dots with the dark green dots.

Now 74 (second one). This one’s a bit harder. Within the group of red and orange dots is a cluster of tinted red and orange dots. That helps form the “2” in “21”. Now the “1” in “21” is formed with the less vibrant green dots found in the “4” of “74”

I’ll let you try the third one now that I shared some insight into how the hidden numbers work.

I like these - I am colour defficent rather than full colour blind and the number on these change before my eyes as I look at them! The same thing happens on the actual test, I can often see both sets of numbers plus the ones which colour normal people can’t see - and they try and call me blind!